The present invention relates to a manipulator device, particularly to a manipulator device for use in a living space.
Although manipulators have mainly been utilized in production fields for assembling or the like, manipulators are expected to be utilized for assisting human activities in living spaces of public facilities of hospitals, or households in the future. Various objects having different hardnesses, weights, shapes, sizes and the like need to be handled when manipulators are utilized in living spaces.
For example, a sensor is arranged at a portion of a manipulator in contact with an object and a control is performed by using information from the sensor. A pressure sensor for detecting a pressure generated between an object and a manipulator is an example of a sensor for such a use. However, in a case where objects vary and hardnesses or weights differ, an operation under a constant pressure is not appropriate, and a pressure generated by a manipulator needs to be changed based on the object. When an object is manipulated by a constant force regardless of the target object, the object may be damaged, or the object may slip from the manipulator's grasp. As a means for resolving the problem, a position of the object relative to the manipulator (slip) is detected and a force is controlled based thereon.
Many sensing systems for detecting slip are possible. When a manipulator is utilized in a living space, it is very important to manipulate a light weight object. In such a case, a force applied to the sensor is very small, and therefore, an optical sensor which does not need to be deformed in order to sense is an option.
It is necessary to set a slip detection point for the object to be manipulated in order to effectively operate an optical slip sensor. Japanese Unexamined Patent Application Publication No. 2010-201538 proposes that an optical slip sensor is mounted to a finger of a manipulator, and the manipulator is provided with finger attitude adjusting means and at least two pressure sensitive elements. Thereby, an angle of the finger is controlled optimally for the slip sensor.